1. Technical Field
The present invention relates in general to safety indicators for vehicles, and in particular to an improved method and system for controlling safety indicators on a towed vehicle.
2. Description of the Related Art
The use of safety indicators on motor vehicles is well-known in the prior art. Such safety indicators include turn signals, brake lights, back-up lights, hazard lights, audible indicators activated when a vehicle backs up, and other similar safety indicators.
When a motor vehicle is used as a towing vehicle for towing a towed vehicle, it is desirable and highly advisable that a duplicate set of safety indicators be attached to the towed vehicle so that drivers behind the towed vehicle may know the status of both the towed vehicle and the towing vehicle. Typically, when vehicles are towed, safety indicators on the towed vehicle are connected to the towing vehicle via a set of wires that provide power to a safety indicator on the towed vehicle that corresponds to a safety indicator on the towing vehicle. This connection of wires between the towed vehicle and the towing vehicle causes several problems.
First, if the towed vehicle has no useable safety indicators, additional safety indicators are typically mounted to the rear of the towed vehicle. Because the safety indicators are typically mounted on the outside of the towed vehicle, wires must be strung from the safety indicators at the rear of the towed vehicle to a connection on the towing vehicle. Many times there is no place to securely attach these wires on the towed vehicle. If these wires are not secured to the towed vehicle, they may be blown about by wind or sag so that they drag along the road. Wires that are blown by the wind may weaken and wear the insulation, which will eventually cause the wires to short circuit. Additionally, wires that blow against the painted surface of a towed vehicle may damage or scratch the surface of the towed vehicle. The paint of the towed vehicle may also be damaged if the wires are attached with an adhesive fastener, such as tape.
Running wires from the rear of the towed vehicle to the towing vehicle also takes time. In many situations, it is important that the towed vehicle be quickly connected to the towing vehicle so that, for example, an accident scene may be cleared by a tow truck. Precious time may be wasted connecting safety indicators with wires. Another problem with connecting safety indicators with wires occurs in the connectors between the towed vehicle and the towing vehicle. These connectors may oxidize or weather over time, and become loose due to abuse or exposure to vibration, all of which may cause such connectors to become unreliable. Additionally, a connector on a towed vehicle may be physically incompatible with a mating connector on the towing vehicle. Such incompatibility may require the use of adapters or require the use of multiple connector types on the towing vehicle to accommodate various towed vehicles.
It is also known in the prior art that auxiliary lighting systems attached to the exterior of a motor vehicle may be wirelessly controlled from the cabin of the vehicle. The purpose of such wireless control is to avoid cutting a hole through the firewall to install wires from the interior of the vehicle through the firewall to the engine compartment where relays that control the power to the auxiliary lighting systems are located. Such a system for wirelessly controlling auxiliary lights is shown in U.S. Pat. No. 5,195,813 to Brown. The invention in Brown, however, is not useful for solving the problem caused by connecting wires between a towing vehicle and safety indicators on a towed vehicle because Brown teaches connecting a wire from a battery in the vehicle that has the transmitter to auxiliary lights on the same vehicle. Furthermore, Brown requires a driver to operate switches from the cabin of the vehicle which would be inconvenient and perhaps unsafe for operating safety indicators on a towed vehicle.
Another problem with wiring safety indicators on a towed vehicle into the electrical system of the towing vehicle occurs with the flasher in the towing vehicle. Many times the flasher in the towing vehicle is not able to accommodate the increase in the electrical load caused by connecting and supplying power to the safety indicators on the towed vehicle. This increase in electrical load may cause the flasher in the towing vehicle to flash rapidly and therefore fail to provide a proper indication.
In summary, known means of connecting and controlling safety indicators on a towed vehicle have the disadvantages of requiring too much time to connect, relying on connections that are abused and subject to harsh environments, damaging the finish on a towed vehicle with blowing wires, overloading flasher circuits in the towing vehicle, and having incompatible electrical connectors between towing and towed vehicles. Because of these disadvantages, a great need exists for a safety indicator control system for towed vehicles that is quickly and easily installed on the towed vehicle, provides a reliable means for activating the safety indicators, eliminates wear and tear on the exterior finish of towed vehicles, and is not distracting to the operator of the towing vehicle as the towing vehicle is driven.